1. Field of the Invention
This invention relates to a method and an apparatus for recycling sand by removing adhering material from sand surfaces, especially for recycling molding sand which has been used for molding a product.
2. Description of the Prior Art
A conventional apparatus that removes foreign material from sand surfaces to reuse molding sand is disclosed in Japanese Utility Model Publication No. 61-35323 (JP, Y, 61-35328). To reuse the sand this apparatus removes or separates foreign material from sand surfaces by feeding the used sand to an impeller to thereby throw it against a wall. However, since in this method the impact given to the sand is so strong, the sand tends to become fine or smaller. This causes a drawback in that the amount of necessary binding material to be added to the molding sand increases when it is reused.
The purpose of this invention is to provide a new apparatus for removing foreign material that adheres to sand surfaces while maintaining the original grain size of the sand.